An earthquake-generating chunk of tectonic plate has been discovered beneath Northern California. It’s attached to the bottom of the North American plate like gum stuck to a shoe.
Using abundant, tiny, nearly imperceptible earthquakes that can help reveal complicated faults beneath Earth’s surface, researchers have identified this previously hidden hazard. The plate may have been the source of the 1992 magnitude 7.2 Mendocino earthquake, researchers report January 15 in Science.
Beneath the peaceful beauty of Northern California’s Lost Coast lies a complicated, restless geologic jumble, one of the United States’ most active tectonic regions. It’s where the San Andreas Fault meets the Cascadia subduction zone. Three sections of Earth’s